50 U.S.C. § 212 : US Code - Section 212: Confiscation of property employed to aid insurrection

      Whenever during any insurrection against the Government of the
    United States, after the President shall have declared by
    proclamation that the laws of the United States are opposed, and
    the execution thereof obstructed, by combinations too powerful to
    be suppressed by the ordinary course of judicial proceedings, or by
    the power vested in the marshals by law, any person, or his agent,
    attorney, or employee, purchases or acquires, sells or gives, any
    property of whatsoever kind or description, with intent to use or
    employ the same, or suffers the same to be used or employed in
    aiding, abetting, or promoting such insurrection or resistance to
    the laws, or any person engaged therein; or being the owner of any
    such property, knowingly uses or employs, or consents to such use
    or employment of the same, all such property shall be lawful
    subject of prize and capture wherever found; and it shall be the
    duty of the President to cause the same to be seized, confiscated,
    and condemned.